Wholly aromatic polyester resins have long been known. For instance, 4-hydroxybenzoic acid homopolymer and copolymers have been provided in the past and are commercially available. Such polymers commonly are crystalline in nature, relatively high melting or possess a decomposition temperature which is below the melting point, and when molten frequently exhibit an isotropic melt phase. Molding techniques such as compression molding or sintering may be utilized with such materials. Representative publications which discuss these wholly aromatic polyesters include: (a) Polyesters of Hydroxybenzoic Acids, by Russell Gilkey and John R. Caldwell, J. of Applied Polymer Sci., Vol. II, Pages 198 to 202 (1959), (b) Polyarylates (Polyesters From Aromatic Dicarboxylic Acids and Bisphenols), by G. Bier, Polymer, Vol. 15, Pages 527 to 535 (August 1974), (c) Aromatic Polyester Plastics, by S. G. Cottis, Modern Plastics, Pages 62 and 63 (July 1975), and (d) Poly(p-Oxybenzoyl Systems): Homopolymer for Coatings: Copolymers for Compression and Injection Molding, by Roger S. Storm and Steve G. Cottis, Coatings Plast. Preprint, Vol. 34, No. 1, Pages 194 to 197 (April 1974). See also, U.S. Pat. Nos. 3,039,994; 3,169,121; 3,321,437; 3,553,167; 3,637,595; 3,651,014; 3,662,052; 3,668,300; 3,723,388; 3,759,870; 3,767,621; 3,773,858; 3,787,370; 3,790,528; 3,829,406; 3,857,814; 3,884,876; 3,890,256; 3,974,250; and 3,975,487; and U.K. patent application No. 2,058,102A.
It has been disclosed that certain polyesters may be formed which exhibit melt anisotropy. See, for instance, (a) Polyester X7G-A Self Reinforced Thermoplastic, by W. J. Jackson, Jr., H. F. Kuhfuss, and T. F. Gray, Jr., 30th Anniversary Technical Conference, 1975 Reinforced Plastics Composites Institute, The Society of the Plastics Industry, Inc., Section 17-D, Pages 1-4, (b) Belgian Pat. Nos. 828,935 and 828,936, (c) Dutch Pat. No. 7505551, (d) West German Nos. 2520819; 2520820; 2722120; 2834535; 2834536 and 2834537, (e) Japanese Nos. 43-223; 2132-116; 3017-692; and 3021-293, (f) U.S. Pat. Nos. 3,991,013; 3,991,014; 4,057,597; 4,066,620; 4,067,852; 4,075,262; 4,083,829; 4,093,595; 4,118,372; 4,130,545; 4,130,702; 4,146,702; 4,153,779; 4,156,070; 4,159,365; 4,161,470; 4,169,933; 4,181,792; 4,183,895; 4,184,996; 4,188,476; 4,201,856; 4,219,461; 4,224,433; 4,226,970; 4,230,817; 4,232,143; 4,232,144; 4,238,598; 4,238,599; 4,238,600; 4,242,496; 4,245,082; 4,245,084; 4,247,514; 4,256,624; 4,265,802; 4,267,304; 4,269,965; 4,272,625; 4,279,803; 4,285,852; 4,287,332; 4,294,955; 4,299,756; 4,314,073; 4,314,688; 4,318,841; 4,318,842; 4,332,759, 4,333,907; 4,335,232; 4,337,190; 4,337,191; 4,339,375; 4,359,569; 4,360,658; 4,362,777; and 3,437,349; (g) U.K. Application No. 2,002,404; and (h) European patent application Nos. 24,499 and 45,499.
Representative disclosures of anisotropic melt forming polyesters, poly(ester-amides) or poly(ester-carbonates) which may include 6-oxy-2-naphthoyl moiety are present in U.S. Pat. Nos. 4,161,470; 4,219,461; 4,256,624; 4,279,803; 4,299,756; 4,318,841; 4,318,842; 4,330,457; 4,337,190; 4,351,917; 4,351,918; 4,355,133; 4,359,569; 4,362,777; and 4,370,466; and commonly assigned U.S. Ser. Nos. 319,024, filed Nov. 6, 1981 (now U.S. Pat. No. 4,371,660), and 401,932 filed July 26, 1982.
In U.S. Pat. No. 4,256,624 a wholly aromatic polyester is disclosed which contains recurring 6-oxy-2-naphthoyl moieties in addition to moieties derived from at least one aromatic diol and at least one aromatic diacid. There is no discussion of providing urea linkages in the resulting wholly aromatic polyester.
See also U.S. Pat. No. 4,219,461 where a wholly aromatic polyester is disclosed which contains recurring 6-oxy-2-naphthoyl moieties, 4-oxybenzoyl moieties, symmetrical dioxyaryl moieties, and symmetrical dicarboxyaryl moieties. Once again there is no discussion of providing urea linkages in the resulting wholly aromatic polyester.
It is an object of the present invention to provide a novel melt processable wholly aromatic polyester urea which possesses more highly polar linkages in the polymer chain than those identified in U.S. Pat. Nos. 4,219,461 and 4,256,624.
It is an object of the present invention to provide an improved wholly aromatic polyester urea wherein the urea linkages contribute a relatively high level of polarity to the polymer chain which beneficially contributes strong electron interactions between adjoining polymer chains and between the polyester urea and other materials, such as rubber matrices, dyes, etc.
It is an object of the present invention to provide an improved melt processable wholly aromatic polyester capable of forming an anisotropic melt phase at a temperature below approximately 400.degree. C., and preferably below approximately 370.degree. C. (e.g. below approximately 350.degree. C.).
It is an object of the present invention to provide an improved wholly aromatic polyester urea which is suited for the formation of quality molded articles, melt extruded fibers, melt extruded films, or for use as a melt adhesive.
It is an object of the present invention to provide improved wholly aromatic polyester urea fibers which particularly are suited for use as fibrous reinforcement in a rubber matrix.
It is an object of the present invention to provide an improved wholly aromatic polyester which readily may be melt extruded to form a film.
It is another object of the present invention to provide an improved wholly aromatic polyester urea which readily may be injection molded to form a molded article (which optionally may be fiber and/or filler reinforced).
It is a further object of the present invention to provide a wholly aromatic polyester which exhibits improved dyeability characteristics and improved bonding characteristics when employed as a melt adhesive.
These and other objects, as well as the scope, nature and utilization of the present invention will be apparent to those skilled in the art from the following detailed description.